JP2000185103A - Guide catheter with soft tip and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter with essential softness at the tip. SOLUTION: Pressure and heat are applied to the base of the soft tip 40 of the end part 35 of this catheter shaft and a tubular sleeve 120 is adhered to the end part 35 to link an attaching/connecting part 55. The end part 35 of the catheter shaft is made to match with the end segment, that is, the base of the soft top, with the sleeve 120 attached to the outside of the attaching/ connecting part 35. A heat contractile tube is attached to a part adjacent to the sleeve and the catheter shaft and the outside of the end segment, the base of the soft tip, and heat is applied to the tube. The materials of the tubular sleeve, catheter shaft and the end segment or the soft top of the end are all melted and energized to fill the gap in the attaching/connecting part 55, reducing the outer diameter of the sleeve 120. After the assembly is cooled and solidified, the heat contractile tube is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Garlev A Satter (G
haleb. A Sterle and others, filed Feb. 10, 1998, Single Piece Hub / Strain, which can be injection molded outside the shaft.
RELIEF THAT CAN BE INJECT
ION MOLDED OVER A SHAFT), commonly assigned US patent application Ser.
1,682 and Nasser Raffine
r. Rafiee) and others in the name of 1998
Having an extruded radiopaque strip embedded in a flexible tip and a method of manufacturing the same (CATHETER HA) filed on March 23, 2010
VING EXTRUDEDRADIOPAQUE S
TRIPES EMBEDDED IN SOFTTI
P AND METHOD OF FABRICATI
ON) US patent application Ser. No. 09 / 046,24.
See No. 1.

[0002] The present invention relates to medical intraluminal catheters, particularly relatively stiff catheters, which can be inserted into a blood vessel through an incision in the patient's skin for the introduction of other devices or fluids for diagnostic or therapeutic purposes. An improved flexible distal tip or segment attachment having a proximal catheter shaft.

[0003]

BACKGROUND OF THE INVENTION A catheter is a tubular medical device that is inserted into a body cavity or blood vessel for diagnostic or therapeutic purposes. Medical intraluminal catheters are specifically designed to be insertable into the vasculature and can be used for diagnostic, interventional (integer) treatment.
It can be used for a wide variety of purposes, including therapeutic therapies, drug administration, drainage, irrigation, and the like. Medical intraluminal catheters for each of these purposes can be introduced to multiple target locations in the patient's body by guiding the catheter to target locations through incisions and blood vessels formed in the patient's skin and through the tubing. Can be.

[0004] Medical intraluminal catheters generally have an elongate catheter side wall enclosing a catheter lumen extending between a proximal end of the catheter body coupled to a relatively stiffer catheter hub and a distal end of the catheter body. And a flexible catheter tube or body.
The catheter body can be relatively straight or essentially curved or curved by inserting a curved stiffening or guide wire through the catheter lumen. The catheter body and the catheter side wall typically retain sufficient side wall flexibility and strength properties to allow the catheter to be used for the intended medical purpose, whilst retaining the outside of the catheter body. Manufactured and dimensioned to minimize diameter and sidewall thickness and maximize catheter lumen diameter.

[0005] One method of treatment applicable to the present invention is known as percutaneous transluminal coronary angioplasty ("PTCA"). PTCA can be performed, for example, to reduce the deposition of cholesterol fat, or atherosclerotic plaque, into arteries. The catheter must be stiff enough to be pushed through the blood vessel and robust enough to control torsion to a high degree. The stiffness and stiffness of the catheter tip risks piercing or damaging the blood vessel when the catheter is twisted in the vasculature. For this reason, it is desirable for the catheter to have a soft or flexible distal tip. However, thin side walls with a thickness of 0.3 mm or less,
And the tendency to have a catheter with a more flexible distal tip, the joint between the flexible distal tip and the catheter shaft is substantially weaker.

No. 5,509,910, issued to Lunn, and commonly owned by Br.
U.S. Pat. No. 5,545,149, issued to U.S. Pat. No. 5,972,867 and others, discloses various prior art methods of attaching a flexible distal tip to a proximal shaft of a catheter and improvements to these methods. Has been described. In the aforementioned U.S. Pat. Nos. 5,509,910 and 5,545,149, an outer tube or sheath, an inner liner surrounding the catheter lumen, and a wire braided reinforcement layer between the outer sheath and the inner liner. And a proximal shaft of a composite catheter formed from the above. In both cases, the flexible distal tip is attached to the distal end of the catheter shaft via the intermediate segment. A typical multi-layer catheter shaft has a wire braid and TEFLON® (polytetrafluoroethylene or PT
The presence of FE) implies that the material used for the flexible tip does not adhere well to the wire braid or Teflon, thus impairing the bond between the catheter shaft and the distal tip segment. Become. For this reason, a transition segment made of a material having a higher tensile strength than the material constituting the flexible tip is used between the distal end of the catheter shaft and the distal tip segment. As a result, the high strength of the transition segment compensates for the loss of bonding force in the case of a multi-layer catheter shaft and provides acceptable bonding strength at the flexible distal tip. Catheter thickness is 0.3
mm or less, and if the flexible tip material is a low tensile strength material, such as Pelletane® polyurethane with a Shore hardness of 80A, to achieve acceptable bond strength It is particularly important to use a high tensile strength material for the transition segment.

In the above-mentioned US Pat. No. 5,509,910, a high tensile strength transition segment selected from the group of thermoplastic elastomers having an ultimate tensile strength of at least 45 MPa comprises a preformed flexible end of a catheter shaft. Injection molded between tip and end. This transition segment encapsulates the modified surface geometry of the distal axis of the catheter and the flexible proximal tip segment,
Injected in the molten state to form an improved lap seam. In addition, the geometry at both the distal end of the long tubular shaft and the surface of the distal tip segment is reduced so as to reduce stress concentrations and increase surface area to achieve full coupling with the distal tip segment. Let it be modified. The use of high tensile strength transition segments in conjunction with the modified surface geometry will significantly improve the tensile strength of the joint between the catheter shaft and the flexible distal tip. In a preferred embodiment, the geometry at the distal surface of the catheter shaft is modified by removing two pawls on either side of the longitudinal central axis of the catheter shaft. Similarly, the removal of the two pawls on either side of the longitudinal center axis of the distal segment alters the geometry at the proximal surface of the distal segment. One alternative embodiment is to remove two or more pawls at either or both the distal end of the catheter shaft and / or the proximal end of the flexible distal segment to further increase the bonding strength.

[0008] In US Patent No. 5,545,149, between the preformed flexible distal tip and the preformed intermediate transition tube or transition segment, and between the transition segment and the proximal shaft of the reinforced catheter. An improved method is disclosed for attaching a flexible tip where a lap seam is formed between the ends. In this case, the preformed parts are assembled on a mandrel and in a heat shrink tube, and the assembly is subjected to IR heating. The heat and pressure applied to shrink the heat shrink tubing causes local melting at the distal end of the catheter shaft and at the abutment end of the transition segment along with the proximal end of the flexible distal tip. After the assembly has cooled and the seam has set, the heat shrink tubing and mandrel are removed.

[0009] Radio frequency (RF) energy has also been employed to thermally couple the preformed flexible distal tip to the wire braided catheter shaft. RF energy is applied to the parts assembled on the mandrel and the heat causes the material to melt at the butt seam.

[0010]

One problem with such an approach is that the lap or butt connection joining the catheter shaft, transition segment, and flexible distal tip has significant pressure and / or heat. These pressures and heat are generated by the concentricity, hardness,
And adversely affect the torsional resistance. Generally, the side wall of the catheter shaft, a flexible distal tip,
And the thickness of any intermediate segment is desirably as thin as possible so as to maximize the inner diameter of the catheter lumen for any particular French sized catheter.
This reduced thickness reduces the bonding surface area of the lap or butt seam and, when heat is applied to form a bond, the sheath material shrinks into the interstitial voids of the braid, resulting in a wire braid. Will be exposed from the thin outer sheath. The exposed braid roughens or undulates the catheter body at the joint, and the thin thickness can weaken the side walls.

Thus, there is a need for an improved flexible tip that provides sufficient bonding strength for catheter shafts having a wall thickness of 0.3 mm or less, and the material of the tip is the concentricity of the catheter shaft. It has essential flexibility without compromising rigidity or torsional resistance.

[0012]

The above object of the present invention is achieved by the following catheter body. That is, in the catheter main body, a proximal tubular catheter shaft formed of a relatively hard material and extending between the proximal end of the catheter shaft and the distal end of the catheter shaft, and having an outer diameter with the catheter shaft. A catheter shaft enclosing at least one catheter shaft lumen extending between the proximal and distal ends of the catheter shaft; and a flexible distal proximal end formed of a relatively flexible material in a tubular form. A distal end of the flexible distal end extending between the distal end of the flexible distal end and the distal end of the flexible distal end, the outer diameter of the flexible distal end substantially equal to the outer diameter of the catheter shaft, and the proximal end of the flexible distal end and the flexible distal end. A flexible distal tip having a flexible distal lumen extending between the distal ends of the catheter tip and the distal end of the catheter shaft adhered to the proximal end of the flexible tip along the mutual attachment joint, Flexible tip lumen & Means for aligning the diameter with the lumen and outer diameter of the catheter shaft, the alignment further comprising a tubular sleeve adhered to the distal end portion of the catheter shaft and the proximal end of the flexible distal end to bridge the mounting joint. And a catheter body.

The above and other objects, advantages and features of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention. The present invention relates to a catheter having a catheter body ending in a flexible distal tip,
In particular, it relates to a guide catheter of the PTCA method. The catheter comprises a long tubular catheter shaft having a proximal end and a distal end, and a flexible, atraumatic and tubular flexible distal end having a proximal end coupled to the distal end of the catheter shaft at an attachment joint. With a tip. According to the invention, the use of a tubular sleeve forms and retains the attachment connection. The tubular sleeve surrounds the mounting joint and extends proximally and distally through the length of the sleeve over the distal portion of the catheter shaft and the proximal portion of the flexible distal tip. The sleeve shrinks under the applied heat and force so that the material of the sleeve melts and adheres to the catheter body and the distal tip, and melts into the mounting joint and the flexible distal tip of the catheter shaft. Glue to the ends. The sleeve is formed of a thin thermoplastic material and the melting causes its diameter and wall thickness to shrink so that the sleeve does not significantly increase the outer diameter of the catheter body.

In a preferred embodiment, the modified surface geometry at the distal end of the catheter shaft is formed by removing two pawls on either side of the longitudinal central axis of the catheter shaft. You. Similarly, the removal of the two pawls on either side of the longitudinal center axis of the flexible distal tip alters the surface geometry at the proximal end of the flexible tip. One alternative embodiment removes two or more claws at one or both of the distal end of the catheter shaft or the proximal end of the flexible tip,
It effectively increases the length of the attachment joint into which the molten material flows, further enhancing the connection of the flexible tip to the distal end of the catheter shaft.

The preferred method of the present invention is to align the proximal end of the flexible distal tip with the distal end of the catheter shaft, where the mounting joint has the flexible distal end irregularly with the distal end of the catheter shaft. There is a step characterized by a gap of the gap caused by the contact. The assembled components are then glued together at their abutting ends, for example, by applying heat, such as RF energy, thereby forming a subassembly of the catheter body. The mandrel is inserted through the catheter lumen of the catheter subassembly, and the tubular sleeve is mounted outside the distal portion of the catheter shaft and the proximal end of the flexible distal tip, such that the sleeve bridges the mounting joint. Apply heat and pressure to the tubular sleeve. The lower distal portion of the catheter shaft and the proximal portion of the flexible tip soften or melt, and the material of the tubular sleeve adheres to the catheter shaft and the distal tip of the flexible distal end.
All gaps in the mounting joint are filled, reducing the outer diameter and wall thickness of the sleeve.

More preferably, the step of applying heat and pressure comprises attaching a heat shrink tube outside the entirety of the proximal portion of the tubular sleeve and catheter shaft and the flexible distal tip. Applying sufficient heat to cause the heat shrink tubing to shrink, thereby causing the heat shrink tubing to exert a force on the tubular sleeve assembly above the distal end of the catheter shaft and the proximal end of the flexible distal tip. To crosslink the attachment joint. After the assembly has cooled, the heat shrink tubing is removed.

The method is for attaching a relatively stiff proximal shaft section to an intermediate, relatively more flexible catheter segment, and for attaching a subsequent catheter segment and for attaching the penultimate catheter segment to the final catheter segment. It can also be applied to attach to the end of a flexible end segment, ie a flexible end.

The sleeve preferably reinforces the butt connection without significantly increasing the outer diameter of the catheter body at each joint where the catheter body is used. In the particular example of using a wire braided catheter shaft, the sleeve covers all exposed wire braided surfaces.
However, it will be appreciated that the present invention may be employed when attaching the flexible distal tip to other forms of catheter shafts or intermediate or transition segments. In addition, the present invention may be employed to attach and / or strengthen the attachment connection of a segment of a multi-segment catheter body.

This summary and purpose of the invention, its advantages and features, point out some of the ways in which the invention solves the difficulties in the prior art, and are intended to distinguish the present invention from the prior art. It is not intended to be limiting in any way with respect to the interpretation of the claims initially included and finally patented in the patent application.

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention has a type having a long catheter body and a catheter hub at a proximal end of the catheter body, wherein at least one catheter lumen extends through the catheter hub and the body to a distal end of the catheter body. The present invention provides an improved structure of the catheter. The catheter body is formed of a catheter shaft having a proximal end of the catheter shaft coupled to a catheter hub, and a relatively short and tubular flexible distal tip coupled to a distal end of the catheter shaft. Such a structure is particularly useful for forming medical intraluminal catheters of a wide range of catheter body lengths and diameters. Such a catheter has an outer diameter of 4 mm (12F), preferably 2.67 mm.
Includes small diameter intraluminal catheters with catheter bodies that are (8F) or less, often less than 1 mm (3F), and are used in neurosurgical diagnostic and interventional methods. Such small diameter intraluminal catheters can also be used in gynecology, the heart system, common interventional radiation procedures, etc.
It is also useful for other procedures to access the vasculature as needed. However, the structure of the present invention is not limited to such small-diameter catheters.
Larger diameter catheters, such as A-balloon catheters, are equally useful.

The medical intraluminal catheter according to the present invention comprises a catheter body having dimensions, specific sidewall structures and geometries selected for the intended use. The catheter body is typically about 40-200 cm
Having a length in the range of typically about 60 cm to 175 cm
Has a length in the range of The outer diameter of the catheter body is
Typically, about 0.33 mm (1 F) to 4 mm (12
F), typically in the range of about 0.66 mm (2F) to about 3.33 mm (10F). The catheter body typically defines an inner lumen having a diameter in the range of about 0.1 mm to 3.6 mm, usually in the range of about 0.3 mm to 3.0 mm, and the catheter has a larger catheter lumen. With a larger outer diameter having a diameter of

FIG. 1 shows the above-mentioned US patent application Ser.
FIG. 1 is a plan view of an exemplary medical intraluminal catheter 10 constructed with a unitary catheter hub and strain relief 60 of the type disclosed in U.S. Pat. Nos. 21,682 and 09 / 046,241. In the illustrated embodiment, a unitary catheter hub and strain relief 60
Is injection molded as a single unit outside the catheter hub and body joint 70 and has a proximal hub portion 90 and a strain relief coil 65. Hub portion 90 surrounds and defines hub lumen 100, which extends to catheter body lumen 25 of catheter body 15.
The proximal end portion 90 of the hub is integrally connected to the proximal end 75 of the strain relief coil 65. The strain relief coil 65 is a continuous coil of constant or variable pitch having a coil turn that decreases in diameter from the proximal end 75 of the strain relief coil to the distal end 80 of the strain relief coil. The wound portion of the strain relief coil 65 is preferably molded outside the distal end of the outer surface of the catheter body 15 at the catheter hub / body coupling 70 and adhered to the outer surface of the catheter body in a spiral pattern. . In this manner, the distal end portion of the outer surface of the catheter body 15 that extends the length of the catheter hub / body coupling portion 70 functions as a mandrel, thus providing a strain relief coil lumen 85.
Is effectively formed. It will be appreciated that this structure is merely one example, and that the present invention may be embodied in a catheter employing any known form of catheter hub.

[0023] The catheter body 15 is typically straight along all or most of its length, that is, the body assumes a straight or linear configuration when no external bending forces are applied. . However, the catheter body 15
Is extremely flexible, so that the body can be advanced through tortuous torsional or bent portions of the patient's vasculature. In some cases, the catheter body 15
May have a distal end of a required shape, including curved and bent portions, selected to facilitate introduction and placement of the catheter 10 in the vasculature (typically outside a separate guidewire). it can. The particular geometry of the bends and / or bends can be selected to suit the intended use of the catheter 10.

In a broad general form of the invention, the catheter body 15 comprises at least one proximal catheter shaft 30 and a flexible distal tip 40, wherein the catheter shaft 30 has the desired characteristics. It can be formed in any acceptable way as can be provided. However, the catheter body 15 may include at least one, and optionally one or more, transition segments, each of the transition segments having a different structure and different mechanical properties. For example, the catheter shaft 30 can be constructed to have a distally increasing flexibility. FIG. 1 is intended to encompass any such structure and to show a catheter completed in accordance with the method of the present invention.

In FIG. 1, the catheter shaft 30 is within 1 cm of the distal end 50 of the catheter body from the unitary catheter hub and strain relief 60, usually 2 to 6 mm, preferably 3.5 m from the distal end 50 of the catheter body.
Extend to m ± 0.50 mm, spaced apart. The proximal catheter shaft 30 is reinforced at the side wall 20 of the catheter shaft, as described below, to provide sufficient longitudinal strength and circumferential strength to advance through the patient's skin incisions and blood vessels and through the tortuous vasculature. Strength (hoop strength)
It is preferable to have The proximal shaft 30 of the catheter can be manufactured in a manner other than that specifically described below to achieve this purpose. However, the structure of the proximal catheter shaft 30 can make the proximal end relatively rigid and pierce the vessel wall as the distal end of the catheter shaft is directed and advanced into the vessel. Flexible distal tip 40 attached to its distal end
Is intended to avoid such danger.

The catheter shaft side wall 20 of the catheter shaft 30
One preferred embodiment of this structure is illustrated in FIGS. The side wall 20 of the catheter shaft is preferably formed in the manner taught in commonly assigned U.S. Pat. No. 5,509,910 and U.S. Ser. No. 09 / 021,682. According to this preferred embodiment of the invention, at least the proximal catheter shaft 30 comprises
Outer tubular sheath 110 and inner tubular sheath 105
And an outer tubular sheath 11 embedded in the polymer and
0 and a wire braided tube 115 held between the inner tubular sheath 105.

Typically, the inner tubular sheath 105 is made of a single material, preferably a fluorocarbon (eg, polytetrafluoroethylene (PTFE)), polyamide (eg, nylon), polyether block amide (PEBA), It is preferably made of a lubricating polymer such as polyolefin or polyimide. It is also possible to form the inner tubular sheath 105 as a laminated structure comprising a non-lubricating outer layer and a layer or coating of a more lubricious material surrounding the inner lumen. In one preferred embodiment, the inner sheath 105 is extruded from PEBAX® polyether block polyamide with a 70D shore hardness, with a sidewall thickness of about 0.03 mm to about 0. 0.08 mm.

The wire braided tube 115 is composed of "warp" and "weft" wire filaments which are braided in the weave pattern of a woven basket wound to form one tube. The wire braided tubing 115 is formed using an inner tubular sheath 105 using conventional weaving techniques.
Can be woven directly on the outside. Alternatively, the wire braided tube 115 can be woven on the outside of the mandrel using conventional braiding techniques and then attached to the inner tubular sheath 105. The wire filament has a very small cross-sectional area while retaining sufficient tensile strength to perform the braiding process. It is preferable to use a flat wire filament made of stainless steel, a shape memory alloy (for example, Nitinol), a polymer fiber or the like. Stainless steel filaments having a flat cross section with a thickness of 0.076 mm are particularly preferred.

Next, a wire braided tube 115 is attached to the outside of the inner tubular
After that, the outer tubular sheath 110 is injection molded outside the wire braided tube 115. The outer tubular sheath 110 can be formed of various materials, but is preferably formed of a thermoplastic material having a hardness in the range of 30A to 74D.
Exemplary materials include polyamide polyether block amides (PEBACS® or BESTAMID®), polyurethane, silicone rubber, nylon, polyethylene, fluorocarbon polymers, and the like. In a preferred embodiment, the outer sheath 110 is made of either a 70V Shore hardness PEBAX® polyether block polyamide or a 74D Shore hardness Vestamide® polyether block polyamide. Injection molded.

In one preferred embodiment, the outer diameter is thus about 2.03 mm to 2.06 mm, and the inner diameter of the catheter lumen is about 1.70 mm to 1.70 mm.
A 6F proximal catheter shaft 30 of 72 mm is manufactured. The thickness of the formed composite sidewall is about 0.33 mm to 0.36 mm. Such a catheter shaft 30 has a circumferential strength or crush resistance to a load of 2 to 7 pounds applied perpendicular to its longitudinal axis. Also, the catheter body is 1968.5598 under standard axial loading conditions.
kPa to 2812.28 kPa (28,000 psi
４０40000 psi). The catheter body formed by the outer sheath, the inner sheath, and the wire-sheathed intermediate sheath is 0.5 pounds for a minimum of 30 ° deflection before the sidewalls twist.
It also has torsional resistance that allows it to withstand moment weight loads.

In a preferred embodiment, the distal end 35 of the catheter shaft 30 is connected directly to the proximal end of the flexible distal tip 40 along the mounting connection 55, and the method described with respect to FIGS. A tubular sleeve 1 which overlies and fills the mounting joint
20 is used for bonding. Flexible distal tip 40
Is tubular and has a sidewall surrounding a flexible distal lumen, which is part of the distal end of the lumen 25 of the catheter body and terminates in an opening 45 at the distal end of the lumen. ing. The flexible distal tip 40 is relatively short overall, and typically has a length in the range of about 1.0 mm to 3.0 cm. The flexible distal tip 40 is
Extends approximately 3.5 mm ± 0.50 mm from the distal end of the first and proximal ends within sleeve 120 sufficiently to allow its proximal end to enter sleeve 120. The side wall of the flexible distal tip 40 is sufficiently flexible so that when it abuts against the side wall of the vessel, the side wall bends slightly but does not puncture the side wall of the vessel.

In this embodiment where no transition segment is employed, the tubular sheath 110 outside the catheter shaft
The selection of the polymer material of the flexible distal tip 40 in relation to the polymer material is also made in consideration of flexural modulus and tensile strength. As mentioned above, the tensile strength must be sufficient to ensure a minimum adhesive strength of 18N between the flexible distal tip 40 and the outer tubular sheath 110 at the attachment joint. The polymer material must be selected such that the ratio of the tensile strength of the flexible distal tip 40 is greater than or equal to 1.25 and the ratio of the flexural modulus is less than or equal to 15.0. As a result of the choice of materials and the improved geometry of the surface of the mating end of the catheter shaft distal end 35 and the flexible distal tip 40, the adhesive strength of the mounting joint 55 is greater than 18N. If the thickness of the catheter is less than 0.3 mm, a minimum tensile strength of 30 MPa is required for the flexible distal tip 30. These conditions are fulfilled without addition of any reinforcing material with a material such as a 55V Shore hardness polyether block-polyamide. The flexible distal tip can be made of a polyether-polyamide material having a Shore durometer of about 40D to 55D.

The flexible distal tip 40 is preformed with an inner lumen, side wall thickness, and outer diameter to accommodate similar dimensions of the catheter shaft 30 (or any intermediate transition segment). Preferably, there is. According to the above-cited U.S. patent application Ser. No. 09 / 046,241, one or more radiopaque strips can be co-extruded with the extrusion of the tubular side wall of the tubing, and the flexible tubing can be removed from the tubing. The distal tip 40 is cut off.

FIGS. 4 to 8 illustrate the sequential mounting steps of the method according to the invention. FIG. 4 illustrates a flexible distal tip 40 that is positioned outside the mandrel 95 and is slip-fit onto the outside of the mandrel 95 so as to align with and attach to the illustrated catheter shaft 30. I have. In the illustrated embodiment, the proximal end 125 of the flexible distal tip 40 and the distal end 35 of the catheter shaft 30 are cut such that each has two complementary V-shaped claw cuts, The type of this cutting portion is described in the above-mentioned US Pat. No. 5,509,910.
U.S. Patent Application Serial No. 09 / 0,098,064, filed in detail in U.S. Pat.
No. 46,241. Also, a method of forming a claw-shaped cut portion is disclosed in the above-mentioned US Pat. No. 5,509,91.
No. 0 and the aforementioned US patent application Ser. No. 09 / 046,241. The term "claw-shaped" refers to Theodore Baum of McGraw-Hill Book Co., New York, NY.
easter), Standard Handbook for Editing Machine Engineers ( Standard Handbook for Me)
chemical Engineers ) pp. 2-1
9-20, “claw-shaped portion (ung) of a right-angle cylindrical body
ula of a right circular c
ylinder) ". However, the method of the present invention also provides a complementary mating distal end of the other catheter shaft for making a butt connection such that the inner diameter of the lumen of the catheter body is constant throughout its length. And it is also possible to employ for the proximal end of the flexible tip.

In FIG. 4, the flexible distal tip and catheter shaft 30 initially extend a Teflon-coated stainless steel mandrel 95 approximately 5.0 cm distally to the distal end 35 of the catheter shaft. About 10.
It is assembled before bonding by inserting it into the catheter lumen 25 to a depth of 0 cm. The stainless steel mandrel 95 provides rigidity and a concentricity to slide fit within the lumen 25 of the catheter shaft and then adhere the distal end 35 of the catheter shaft to the flexible distal proximal end 125 at the mounting joint 55. It is a dimension that can keep. The flexible distal tip 40 is advanced and rotated outside the distal end of the stainless steel mandrel 95, as shown in FIG.
The complementary claw cuts at the distal end 35 of the catheter shaft and the proximal end 125 of the flexible distal end are aligned in an interlocking engagement along the mounting joint 55. The complementary claw-like cut at the distal end 35 of the catheter shaft and the proximal end 125 of the flexible tip will result in irregular contact points due to the cutting method.
A gap is created between the mounting joint 55 and the mounting joint 55 along its length.

At this point, the components illustrated in FIG. 4 include the distal end 35 of the catheter shaft and the proximal end 12 of the flexible distal end.
Local heating is provided around the complementary claw-shaped cuts of 5, for example by applying high-frequency energy. As the material at the abutment ends melt together, a sub-assembly of the catheter shaft 30 and the flexible distal tip 40 is formed. During this process, the reinforced wire braided tube 115 just proximal to the coupling 55 may be exposed due to melting and shrinkage of the tubular sheath 110 outside the catheter shaft.

In FIG. 5, a sleeve 120 is slip-fit over the catheter shaft 30 and the flexible distal tip 40, the sleeve being above and covering the mounting joint 55. The sleeve 120 is preferably formed from a Pebax (R) polyether block-polyamide tube with a Shore hardness of 40D without any added reinforcement material. Sleeve 12
0 can be made of a polyether-polyamide material having a Shore durometer of about 40D to 55D. The sleeve 120 preferably has a tube thickness of 0.76 mm and a length of 5.0 mm. The inner diameter of the sleeve 120 is sufficiently larger than the outer diameter of the catheter body so that the sleeve has a flexible distal tip 40 and catheter shaft 30.
Is selected so as to slide on the outside of FIG.

After placing the sleeve 120 as shown in FIG. 5, a further heat shrink tube 130 (shown in cross section in FIGS. 6 to 8) is fitted to the outside of the sleeve 120 as shown in FIG. The heat shrink tube extends proximally a distance of about 50 mm from the proximal end of sleeve 120 and extends through sleeve 12.
Approximately 13.5 m to the end of zero and outside the mandrel 95
Extends in the m-terminal direction. Next, heat is applied to the assembly of FIG. 6 to cause the heat shrink tubing 130 to be inserted into the sleeve 120 and the flexible distal tip 40 and the catheter shaft 3 as shown in FIG.
Shrink tightly against the 0 part. The sleeve 120 and its lower flexible distal tip 40 and a portion of the outer and inner layers 110, 105 of the catheter shaft are melted and complementary pawls at the distal end 35 of the catheter shaft along the length of the mounting joint 55. Heating is continued for a period of time sufficient for the plastic material to flow into and fill the interstitial space between the cut-off portion and the proximal end 125 of the flexible tip. The heat shrink tube 130 is preferably made of Teflon FEP (fluorinated ethylene propylene) which does not melt or mix the catheter body and sleeve material. When the heat-shrink tube 130 contracts, a compressive force is applied to the thin-walled sleeve 120, pressing the sleeve against the soft distal tip 40 and the surface of the catheter body 30. The sleeve 120 is compressed from this initial thickness of about 0.76 mm to a thin membrane thickness of about 0.38 mm, which increases the outer diameter of the catheter body only slightly.

In FIG. 8, the heat shrink tubing 130 is cut along its length using the blade 135, taking care not to cut the lower sleeve 120, and the catheter formed as shown in FIG. The main body 15 is exposed.
In FIG. 9, the thickness of the sleeve 120 is exaggerated over the thickness actually achieved using this method for this material and the thickness of the sleeve described above. In practice, the tubular sleeve has an outside diameter that is 2.108 mm to 2.159 mm larger than the outside diameter of the catheter shaft and the flexible distal tip. The thickness of the sleeve 120 is barely noticeable by contact or visual, and the sleeve 120 is colored differently than the color of the catheter shaft 30 and the flexible distal tip for identification. You know only that it exists.

The composite catheter body wall at the mounting joint 55 is illustrated in FIG. A fusion zone is formed along the attachment joint 55, the fusion zone comprising a distal end 35 of the catheter shaft and a proximal end 12 of the flexible distal end.
5 (shown in FIG. 4) are filled so as to fill all interstitial voids due to irregular points of contact with each other. The material of the fusion zone includes the material of the sleeve 120, the material of the flexible distal tip 40 and the inner layer 110 of the catheter shaft.
And the material of the outer layer 105.

The modified geometry of the surface of the flexible distal proximal end 125 and the distal end of the catheter shaft 35 increases the bonding surface area of the butt weld area, and the butt weld area 55
The stress concentration along the line. As a result of the use of interlocking pawls, the surface area is increased by 200% over the surface area of a simple butt seam. In addition, the surface area of the distal end 35 of the catheter shaft is reduced to 110 of the surface area of the frustoconical seam.
% To 200%. In addition, the catheter shaft 30
The angled surface defining the attachment joint 55 between the flexible distal tip 40 and the flexible distal tip 40 is not perpendicular to the tensile and bending loads applied to the flexible distal tip 40 during use, thus providing flexibility. The stress concentration provided by the connection of the tubular elements is reduced at the catheter shaft 30.

In an embodiment comprising three segments (or more) of the catheter body 15, the transition segment is located within 30 cm of the distal end 50 of the catheter body, typically 1 cm from the distal end 50 of the catheter body. At a distance of 10 cm, it is located just distally from the distal end of the catheter shaft at the mounting joint. In this embodiment, the flexible distal tip 4
0 extends distally from the end of the transition segment. This transition segment has a moderate level of reinforcement that provides a moderate level of stiffness, longitudinal load and circumferential strength between the high level of the catheter shaft 30 and the low level of the flexible distal tip 40. I have. As a result, the transition segment has a moderate level of sidewall flexibility between the low level of flexibility of the catheter shaft 30 and the high level of flexibility of the flexible distal tip 40.

When a transition segment is used, the material for the transition segment is selected based on the tensile strength with the polymer comprising the catheter shaft 30, processing temperature compatibility, and flexural modulus. The material is selected to have a minimum tensile strength corresponding to the outer diameter and wall thickness of the catheter body.

When an intermediate portion or transition segment is employed, as described above with respect to the preferred embodiment,
Sleeve 120 is itself elongate so as to extend over the distal portion of catheter shaft 30 and the proximal portion of the flexible distal tip. Alternatively, an additional separate sleeve, similar to sleeve 120, may be placed to bridge the additional attachment connection between the abutting distal and proximal ends of the abutting catheter shaft 30 and the transition segment. it can. The same technique can be employed for any number of intermediate segments. In all such cases, to minimize the thickness of the sleeve 120 and to provide a strong bond area between the sleeve and the lower portion of the catheter shaft and the outer wall of the segment portion adjacent each of the mounting joints. 4 to 8 are performed.

In all such cases, if the catheter shaft, the intermediate segment, and the flexible distal tip polymeric material are selected to be melt compatible within the typical temperature range, the abutting attachment joints , A strong adhesive portion can be formed. The above-mentioned Bestamide and Pebax® polyether block polyamide tubing materials with different Shore hardness have compatible melting temperatures and adhere well to each other.

Although particular embodiments of the present invention have been described in some detail, this description has provided a method for defining equivalents of structures and methods not specifically described or described. And form the basis for
It is intended to describe the present invention. The inventor has stated that the claims are now well known,
It is intended to cover the above-described embodiments and their equivalents that exist during the term of the patent. Thus, it is contemplated that various changes, changes or modifications may be made to the invention described herein without departing from the spirit and scope of the invention as set forth in the appended claims. .

[Brief description of the drawings]

FIG. 1 is a plan view of an exemplary medical intraluminal catheter configured with a flexible distal tip incorporating an upper sleeve in accordance with one preferred embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the relatively stiff catheter shaft along line 2-2 of FIG.

FIG. 3 is a section of a relatively stiff catheter shaft stripped posteriorly to show an inner tubular sheath, an outer tubular sheath, and a wire braided tube held between the inner and outer tubular sheaths. It is a perspective view of.

FIG. 4 illustrates one preferred method of attaching a flexible distal tip to the distal end of a catheter shaft along a mounting joint by employing a method of molding a sleeve of thermoplastic material outside the mounting joint. It is a top view showing a step.

FIG. 5 is a diagram showing steps similar to those in FIG. 4;

FIG. 6 is a diagram showing steps similar to those in FIG. 4;

FIG. 7 is a diagram showing steps similar to those in FIG. 4;

FIG. 8 is a diagram showing steps similar to those in FIG. 4;

FIG. 9 is a plan view of the sleeve above the mounting joint.

FIG. 10 is an enlarged sectional view of the catheter wall formed along section line 10-10 of FIG. 9;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Medical intraluminal catheter 15 Catheter main body 20 The side wall of a catheter shaft 25 The lumen of a catheter main body 30 The shaft of the proximal end of a catheter 35 The end of a catheter shaft 40 The tip of a flexible end 45 The end opening of the lumen 50 The end of the catheter main body 55 Attachment Joint 60 Unitary catheter hub and strain relief 65 Strain relief coil 70 Catheter hub and body coupling 75 Strain relief coil proximal end 80 Strain relief coil distal end 85 Strain relief coil lumen 90 Hub end Portion 95 Mandrel 100 Hub Lumen 105 Inner Tubular Sheath 110 Outer Tubular Sheath 115 Wire Braided Tubing 120 Tubular Sleeve 125 Flexible Tip Base 130 Heat Shrink Tubing 135 Blade

Claims (36)

[Claims] 1. A catheter body, comprising: a proximal tubular catheter shaft formed of a relatively stiff material and extending between a proximal end of the catheter shaft and a distal end of the catheter shaft; A catheter shaft enclosing at least one lumen of the catheter shaft having a diameter and extending between the proximal and distal ends of the catheter shaft; a flexible tip formed of a relatively flexible material in a tubular form and having a flexible tip; A flexible distal end extending between the proximal end of the flexible distal end and the distal end of the flexible distal end, the outer diameter of the flexible distal end substantially equal to the outer diameter of the catheter shaft; A flexible distal tip having a flexible distal lumen extending between the distal ends of the flexible distal end, and a distal end of the catheter shaft adhered to the proximal end of the flexible distal end along the mutual attachment joint; This allows for a flexible tip lumen And a means for aligning the outer diameter with the lumen and outer diameter of the catheter shaft, further comprising a tubular sleeve adhered to the distal portion of the catheter shaft and the proximal portion of the flexible distal tip to bridge the mounting joint. Alignment means having
The catheter body. 2. The catheter according to claim 1, wherein
A catheter wherein the tubular sleeve has an outer diameter slightly larger than the outer diameter of the catheter shaft and the flexible distal tip. 3. The catheter according to claim 2, wherein
The mounting joint is characterized by interstitial voids due to the irregular contact of the proximal end of the flexible tip with the distal end of the catheter shaft, and the material of the tubular sleeve, the catheter shaft and the distal end of the flexible distal end may have a melting temperature range. The attachment joint is selected to be compatiblely melted together within, and the attachment joint is formed, at least in part, from a fused and biased tubular sleeve material within the attachment joint, the flexible distal tip and the catheter shaft material. Fills the interstitial space of the mounting joint. 4. The catheter according to claim 3, wherein
At each of the distal end of the catheter shaft and the proximal end of the flexible tip,
A similar plurality of claw cuts are formed that are complementary to each other in shape, whereby the flexible claw at the proximal end and the claw at the distal end of the catheter shaft along the mounting joint are formed. A catheter adapted to be aligned with the claw-shaped cut portion and the claw-shaped cut portion. 5. The catheter according to claim 4, wherein
A catheter wherein the catheter shaft is formed of a wire braided tube encased within a polymeric outer tube and a polymeric inner tube. 6. The catheter according to claim 5, wherein
A catheter wherein the catheter shaft is at least partially formed of a polyether-polyamide material having a Shore durometer of at least 70D. 7. The catheter according to claim 6, wherein
The flexible distal tip has a Shore durometer hardness of about 40
A catheter formed of a D-55D polyether-polyamide material. 8. The catheter according to claim 7, wherein
The sleeve has a Shore durometer hardness of about 40 D to 5
Formed of a 5D polyether-polyamide material,
catheter. 9. The catheter according to claim 1, wherein
The mounting joint is characterized by interstitial voids due to irregular contact of the proximal end of the flexible tip with the distal end of the catheter shaft, and the material of the tubular sleeve, the catheter shaft and the distal end of the flexible distal end can be in the melting temperature range. The attachment joint is selected to be compatiblely melted together within, and the attachment joint is formed, at least in part, from a fused and biased tubular sleeve material within the attachment joint, the flexible distal tip and the catheter shaft material. Fills the interstitial space of the mounting joint. 10. The catheter of claim 9, wherein each of the distal end of the catheter shaft and the proximal end of the flexible distal end has a similar plurality of claw-shaped cuts that are complementary in shape. The catheter wherein the proximal claw cut at the flexible distal end is aligned with and mates with the claw cut at the distal end of the catheter shaft along the mounting joint. 11. The catheter according to claim 10, wherein the catheter shaft is formed by a wire braided tube encased in a polymeric outer tube and a polymeric inner tube. 12. The catheter according to claim 11, wherein the catheter shaft is at least partially formed of a polyether-polyamide material having a Shore durometer of at least 70D. 13. The catheter of claim 12, wherein the flexible distal tip is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 14. The catheter of claim 13, wherein the sleeve is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 15. The catheter of claim 1, wherein each of the distal end of the catheter shaft and the proximal end of the flexible tip are formed with a plurality of similar claw-shaped cuts that are complementary in shape. The catheter wherein the proximal claw cut at the flexible distal end is aligned with and mates with the claw cut at the distal end of the catheter shaft along the mounting joint. 16. The catheter according to claim 15, wherein the catheter shaft is formed by a wire braided tube encased in a polymerized outer tube and a polymerized inner tube. 17. The catheter according to claim 16, wherein the catheter shaft is at least partially formed of a polyether-polyamide material having a Shore durometer of at least 70D. 18. The catheter of claim 17, wherein the flexible distal tip is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 19. The catheter of claim 18, wherein the sleeve is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 20. The catheter according to claim 1, wherein the catheter shaft is formed of a wire braided tube encased in a polymeric outer tube and a polymeric inner tube. 21. The catheter according to claim 20, wherein the catheter shaft is at least partially formed of a polyether-polyamide material having a Shore durometer of at least 70D. 22. The catheter of claim 21, wherein the flexible distal tip is formed of a polyether-polyamide material having a Shore durometer of about 40D to 55D. 23. The catheter of claim 22, wherein the sleeve is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 24. The catheter of claim 1, wherein the catheter shaft is at least partially formed of a polyether-polyamide material having a Shore durometer of at least 70D. 25. The catheter of claim 1, wherein the flexible distal tip is formed of a polyether-polyamide material having a Shore durometer of about 40D to 55D. 26. The catheter of claim 1, wherein the sleeve is formed from a polyether-polyamide material having a Shore durometer of about 40D to 55D. 27. A catheter body comprising: a proximal tubular catheter shaft formed of a relatively stiff material and extending between a proximal end of the catheter shaft and a distal end of the catheter shaft; A catheter shaft enclosing at least one catheter shaft lumen having a diameter and extending between a proximal end and a distal end of the catheter shaft; and a base formed of a relatively flexible material in tubular form and having a segment. A distal segment of a catheter extending between the end and the distal end of the segment, the outer diameter of the segment being substantially equal to the outer diameter of the catheter shaft, and the segment extending between the proximal end of the segment and the distal end of the segment. A distal segment of the catheter having a lumen of: and a distal end of the catheter shaft adhered to the proximal end of the segment along the mutual attachment joint, A means for aligning the lumen and outer diameter of the segment with the lumen and outer diameter of the catheter shaft, wherein the means is adhered to the distal portion of the catheter shaft and the proximal portion of the distal segment to bridge the attachment joint Alignment means further comprising a tubular sleeve.
The catheter body. 28. The catheter according to claim 27, wherein the mounting joint has a clearance gap due to irregular contact of the proximal end of the segment with the distal end of the catheter shaft, the tubular sleeve, the catheter shaft and The material of the distal segments is selected to melt compatible together within the melting temperature range, and the mounting joint is formed at least in part from a molten and biased tubular sleeve material within the mounting joint; A catheter wherein the material of the distal segment and the catheter shaft fills the interstitial space of the mounting joint. 29. The catheter of claim 28, wherein each of the distal end of the catheter shaft and the proximal end of the segment is formed with a plurality of similar claw cuts that are complementary to each other in shape. A catheter wherein the proximal claw section of the segment is aligned with and mates with the distal claw section of the catheter shaft along the mounting joint. 30. A method of manufacturing a catheter body, comprising: a proximal tubular catheter shaft formed of a relatively hard material and extending between a proximal end of the catheter shaft and a distal end of the catheter shaft; Providing a catheter shaft enclosing at least one catheter shaft lumen having an outer diameter and extending between a proximal end and a distal end of the catheter shaft; and a tubular configuration of a relatively flexible material. And a distal segment of the catheter formed between the proximal end of the segment and the distal end of the segment, the outer diameter of the segment being substantially equal to the outer diameter of the catheter shaft; Providing a distal segment of the catheter having a lumen of the segment extending between the distal ends; and connecting the tubular sleeve to a distal portion of the catheter shaft. And gluing to the proximal portion of the distal segment, bridging the attachment joint and adhering the distal end of the catheter shaft to the proximal end of the segment along the mutual attachment joint, thereby providing the lumen and exterior of the segment. Adjusting the diameter to the lumen and outer diameter of the catheter shaft. 31. The method according to claim 30, wherein the bonding step aligns the proximal end of the segment with the distal end of the catheter shaft so that the mounting joint prevents the proximal end of the segment from being distal to the distal end of the catheter shaft. Characterizing the interstitial voids resulting from contacting the rule; heating the mounting joint so that the proximal end of the segment can be adhered to the distal end of the catheter shaft; and a distal portion of the catheter shaft. Attaching a tubular sleeve outside the proximal portion of the distal segment and bridging the attachment joint; and applying heat and pressure to the tubular sleeve, the distal portion below the catheter shaft, and the proximal portion of the distal segment. To further fuse and attach the material of the tubular sleeve, catheter shaft and distal segment. To, to fill a gap void of the mounting coupling section, further comprising the step of reducing the outer diameter of the sleeve, the method. 32. The method of claim 31, wherein the step of applying heat and pressure includes attaching a heat shrink tubing outside the tubular sleeve and the tubular sleeve and the distal segment outside the distal portion of the catheter shaft. Providing sufficient heat to contract and apply heat to the heat shrink tubing outside of the proximal section assembly and to provide sufficient heat to crosslink the mounting joint, and the material of the tubular sleeve, catheter shaft and distal segment. Melting and biasing the heat shrink tubing to fill interstitial voids in the mounting joint so that shrinkage of the heat shrink tubing reduces the outer diameter of the sleeve. Further comprising the step of removing
Method. 33. The method according to claim 32, wherein the distal end of the catheter shaft and the proximal end of the segment are formed to include a plurality of similar claw cuts that are mutually complementary in shape. The method further comprising the step of aligning further comprising the step of aligning and aligning the proximal claw cut of the segment with the distal claw cut of the catheter shaft along the mounting joint. 34. The method of claim 31, wherein the distal end of the catheter shaft and the proximal end of the segment are formed to include a plurality of similar claw-shaped cuts that are mutually complementary in shape. The method further comprising the step of aligning further comprising the step of aligning and aligning the proximal claw cut of the segment with the distal claw cut of the catheter shaft along the mounting joint. 35. The method of claim 30, wherein the distal end of the catheter shaft and the proximal end of the segment are formed to include a plurality of similar claw cuts that are mutually complementary in shape. The method further comprising the step of aligning further comprising the step of aligning and aligning the proximal claw cut of the segment with the distal claw cut of the catheter shaft along the mounting joint. 36. The method of any of claims 30-35, wherein the distal segment of the catheter comprises a flexible distal tip that provides an atraumatic distal tip of the catheter body.